Problem behaviors such as school misconduct, underachievement, and dropout; tobacco, alcohol, and other drug use; violence and delinquency place youth at an increased risk for school failure, involvement in the criminal justice system, and chronic substance abuse. Researchers in the PRB have developed a program of research focused on this area. One study employs a randomized quasi-experimental design to test the protective effects of exposure to a social skills curriculum, enhanced school environment, and parent education in the special intervention group compared to problem behavior in a comparison group receiving usual education only. Approximately 2 cohorts totaling 2700 students in 7 middle schools were followed through the 6th, 7th, 8th and 9th grades. Approximately half received the special intervention. In multi-variate analyses association with problem behaving peers and low levels of self control consistently have been found to be risk factors, and parent monitoring and parent expectations for behavior have been found to be protective factors. Bivariate analyses of the efficacy of the intervention have revealed few, very modest effects which have not held in multivariate analyses. Data analyses examining the first two time points (early 6th grade and late 6th grade) are complete and have resulted in several publications and manuscripts under review. Longitudinal analytic techniques are being used in the ongoing work. A contract for a second randomized trial has been awarded and planning is underway. This study will focus on the reduction of aggression and violent behavior among middle school students. It will combine individual mentoring and small group social skills building approaches with a population of at-risk youth.